oN THE BACK OF THE AMP THERE WILL BE AN R.C.A. JACK LABELED SUB OUT. Use this only then run an r.c.a. cable to your sub You may have 2 inputs on your sub labeled sub in L+R then just get a r.c.a. y conector . then turn your volume control all the way off and bring up the level that sounds rite to you you shouyld never go more than a third way up on the level in closing run a test tone on your amp and set the sub to 0 d.b. good luck
I have an Onkyo 780 and some guy at Home Depot said I could use the existing r59 coaxial cable that was under my house to hook up the subwoofer. I put on the jacks and it did work, so I was pretty happy, until my wife said that the subwoofer started giving really loud feedback. She had to unplug the subwoofer.
I was wondering if the coax cable is the problem? It is plugged into the wall, away from the TV, and about 1 foot next to the left speaker. I have the front speakers set to "large," and the subwoofer turned all the way up (otherwise it didn't turn from standby to on).